Life Span of Cryogenically Stored Stem Cells

Cryogenic storage (from the Greek word kryos, "cold"), or hibernation in liquid nitrogen or nitrogen gas, means that cells are frozen at very low temperatures (down to -196°C) such that the water they contain turns to ice and the molecular processes of cellular metabolism stop.

The low temperature interrupts the chemical and biological processes that normally cause cell deterioration, and guarantees safe storage of the genetic material over a very long period of time.

To date, the longest cryogenic storage has been 23 years before the sample was thawed (H.E. Broxmeyer, M.R. Lee et al., 2011). However, there are no known reasons that would lead to significant damage of stem cells stored cryogenically over even longer periods. The FDA and EMFA (institutions that monitor European and international storage of biological materials) have published no restrictions on the use of stem cells stored for periods longer than this.

Additionally, research on and use of deep-frozen human cells (bone marrow, sperm, etc.) show that cryogenic storage preserves cell viability for decades. The longest period of cryogenic storage after which human cells have been successfully used is 50 years.